Elastomeric electrical connectors of the type disclosed in U.S. Pat. No. 3,985,413 are sold by AMP Incorporated of Harrisburg, Pa. under the trademark AMPLIFLEX and are commercially available in many different geometries. One of these geometries is a relatively tall and thin connector 10 which is shown in FIGS. 1 and 2. The connector 10 includes an elastomeric core 12 and a flexible film 14 having circuit traces 16 thereon wrapped around the core. The connector 10 is housed between walls of a slot 2 in a dielectric housing 4 and is compressed between opposed substrates 5 and 6 on opposite sides of the housing. The substrates have respective sets of electrical contact pads 7a, 7b, 7c and 8a, 8b, 8c. The pads 7b and 8b are electrically interconnected by the circuit traces 16 on the connector 10.
In an uncompressed state, the connector 10 has curved surfaces at upper and lower ends 18, 19, and has a uniform width between the ends. As the connector is compressed in the vertical or elongation direction, natural tackiness of the core 12 keeps the flexible film 14 substantially adhered to the sides of the core and prevents the film from buckling. This compression causes the core to swell and causes the ends 18, 19 of the core to distort to a flat shape. This distortion causes the film to separate from the core. As a result, a portion of the film and circuitry may collect near an end of the connector, thereby leading to problems in the form of pinched circuitry and electrical shorting to adjacents rows of contact pads 7a, 7c, 8a, 8c on the substrate. In FIG. 1, the slot 2 has beveled edges 3 to provide space in which loose circuitry 22 can collect. This slot design alleviates pinching of the circuitry, but shorting to adjacent contact pads can still occur. In FIG. 2, the slot does not have beveled edges. This slot design hinders shorting but causes pinching of loose circuitry 24 which may lead to shorting as well. There is a need for an elastomeric electrical connector which overcomes these problems.